Traditionally, during television programs, viewers have been limited in the ability to control the content of a program being viewed. For example, during a television commercial segment or any other segment that may not be of immediate interest, viewers have been either forced to view the entire segment or change the channel and wait for the segment to conclude. The advent of video cassette recorders (VCRs) allowed viewers greater control over the content of segments when the program was pre-recorded. In recent years some VCR systems have included a relatively unsophisticated one-touch commercial skip feature. The feature consists of little more than a mechanism for automatically fast-forwarding the playback of video data by thirty seconds. By pushing a single button, the VCR automatically advances the video tape by the estimated length of an average commercial segment. While this feature introduces the convenience of a one-touch skip, the length of the skip does not always correspond with the length of a segment that is not of immediate interest to the viewer and is particularly ill-suited for identifying many program transitions that do not have predictable durations.
The advent of digital video formats has allowed for many conveniences not considered practical for a traditional VCR system. Such digital video formats, in particular the Moving Pictures Experts Group (MPEG) and other video compression formats, allow for more sophisticated segment skips. For example, a viewer using a digital video data system that records digital video data in a digital video record on a hard disk or another mass storage device may skip or replay to predetermined scenes, without the time consuming fast forward or rewind of a video tape.
Although digital video systems can more conveniently jump from one portion of a video program to another without having to physically advance a tape, conventional digital video data systems have also generally been capable of advancing between video segments at predetermined increments, such as at thirty-second intervals. Thus, viewers of recorded video data, whether using VCR systems or digital video data systems, have generally been constrained to advancing the video playback in certain, restrictive ways. For instance, the viewer can cause the playback to be skipped ahead by thirty seconds. Alternatively, viewers who wish to advance the playback of a video program past one or more commercials to the beginning of the next non-commercial segment have been forced to place the VCR or digital video data system in a fast-forward mode and then visually identify, by trial and error, the position that represents a segment transition. Accordingly, for entertainment systems that are capable of playing back a stored video program received from a television broadcast system, there is a need for a technique to identify the presence of the one or more commercials in the digital video record so that a playback of the digital video record can use this identified presence during any playback thereof.